THE KUMARA SLUDGECHANNEL.

Kumara Times, Issue 1472, 16 June 1881, Page 2

THE KUMARA SLUDGECHANNEL.

For some time past we have been purposing to furnish our readers and the public generally with some idea of the progress of work in connection with the construction of the Kumara sludgechannel, and at the same time to give some description of the' work itself; and for this purpose we yesterday devoted ourselves to the self-imposed task. The first shaft of Section No. 2 (or Contract No. 2) of the Kumara sludgechannel is about half-an-hour's walk from the town, along the old tramway to Dunedin Flat. At the flat the tramway branches off in a south-west-erly direction to what is known as Larrikins Terrace. The shaft of Section No. 1 (Maher's contract) is first reached along this course, and the distance between these two shafts is from 8£ to 9 chains. Section No. 1 is completed with the exception of blocking the channel. Making known the object of our visit to Mr O'Connor, one of the contractors, that gentleman at once proceeded to give the desired information. There are about 63 men employed on this second contract, and seven or eight horses ; 37 hands are actually working in the channel at the three faces and are divided into five shifts ; 8 are at work on the surface, 4 fitting timber, 4 attending to shaft, 10 are getting sawn timber from Blackwater Creek, and the others are engaged in drawing laths and timber, with eight horses. Some time, it will be remembei"ed, elapsed between the signing of the contract for Section No. 2, (which Was effected on the Ist December, 1880) and commencing work, owing to the Christmas holidays. But although this section, was not begun till two mouths afterwards, last February, there is every probability of its being completed well within the date fixed, the 15th September, as the contractors expect to finish it in about ten weeks from this time, thus leaving three weeks to spare. The whole length of this second contract is 39 chains. Two shafts have been sunk j and thus four faces were worked at simultaneously. The junction of the two channels from Price and Connor's first shaft to Maher's No. 1 contract was effected several weeks ago. Section No. 2 is '39 chains in lenpth; the caps are lOin. by 10in., and 7ft. long; the legs 6in. by Bin., and 7ft. long ; laths, Bin. by 2in., sft. long. The width of this section is 3ft. less than No. 1, as it was thought that one tramway would be sufficient to work the upper end of the channel. The tramway will be on the right hand side going op the tunnel, i.e. towards the south. The rise is 2.39 feet per chain, or 1 in 27.61, or about 6in. to the box of 12ft, and a little more at the curvp. An ingenious labor-saving device is adopted at both shafts. The first is a double shaft. A tank full of water is

let down One shaft, which causes the full truck in the adjoining shaft to be hoisted up; and, whilst the water is let out of the tank at the foot of the shaft to pursue its course down the channel, the loaded truck is emptied, and when put in position again, beiug a little heavier than the now empty tank, it is made to descend and force the tank gently up, the tank with water and the truck being adjusted to such an equal balance. The same principle is adopted at the further shaft, except that as there would be no outlet or escape for the water at the bottom of the shaft} the tank is made to run on an inclined plane, and the water discharged into a small Stream on the ground surface, several feet of course away from the shaft. After obtaining the foregoing particulars, Mr O'Connor kindly showed ns down the first shaft, and up to the face. There were four men actually at work, two breaking away the face, and two handling the : trucks to and from the face and the shaft. We were at once impressed with the apparent stability of the structure, and the means adopted for the future protection of life as compared With the original specifications of No. 1 contract. The legs are braced longitudinally throughout the channel, the braces being 9in. by 3in. and 12ft. in length j these are. joined with lapping pieces and bolted. Iron dogs are used to brace the legs together as the work proceeds, and when thei*e*are three legs in position, the bracing is continued. . Returning to the foot of the shaft we proceeded downwards toward No. 1 section, or what is more generally known as Maher's contract. This is 46 chains in length. The caps, which are of black birch, are lift. 4in. long, by 12in. by 12in. thick. The legs are of heart of red pine sft. 6in., and ten feet clear.from leg to leg. The tunnel is lathed at top and sides with 2in. heart of red pine. In this section there is a tramway on each side the channel. The channel is . 3ft. 6in. wide, and 3ft. in depth throughout the length of the tunnel; but when the blocks, which will be 6ia. .thick-are put i«,. the depth will of course be only 2ft. 6in. Standing in the bed of the channel, this section looks more as if it were intended for a railway tunnel than for the .purposes of a sludge-channel. Since the memorable afternoon of the 6th-July last year, when three valuable lives were lost during the work of construction of this first section, owing to the. strong representations made, the Government resolved not only to have the legs continuously braced, but'to place an intermediate set twixt every third set. By this and the bracing, the original contract price of the first section £6BOO, was increased to a cost of about £9OOO. Messrs Price and O'Connor's contract pi ice for the second section is £5590, with a penalty of £2O per week for every week after the loth September it may remain unfinished. The blocks are to be 20in. square, Gin. thick, and placed diagonally. We concur with Mr Gow that if these were made 2lin. instead of 20in., by cutting an inch off the corner which joins the lining boards, it would facilitate their being placed and securely held in position. It is to be hoped no time will be lost in placing the blocks in the channel. We are indebted also to Mr Gow, Overseer of Works in the district, for some of' the particulars given above ; and he informs us that the total actual length of the tunnel is 80 chains. There will be an open tail-box to the Teremakau River of 16 chains. The total length of the channel as surveyed, will be 101 chains, but five chains of the upper end of Messrs Price and O'Connor's section are not to be constructed, as those parties of miners who have claims and areas at that end will be able to put their own drives in. We observed one drive already into the channel; this is the work of M. Borlase and party, who were one of the first to apply for a double-area claim! Mr Hopkins, one of the party who happened to be down, showed us up the drive, which is quite ready, boxed and everything, to the full length, 450 feet. Harris and party's drive is also nearly completed. The first section of the sludge-channel is nearly due N. and S.; the second section inclines to the S.E., looking towards the upper end. Now comes the all-important matter of bringing in a sufficient supply of water to work the channel, without which all this expenditure must be as so much money thrown away. On very good authority we are told it will require 20 to 30 heads of water coutinually, during working hours, to prevent the channel being blocked with debris by miners sluicing; and this quantity will have to be increased in proportion as the number of claims using the channel increases.